A Look Inside Your Pregnant Brain

Kayt is a member of the American Society of Journalists and Authors (ASJA), the Author's Guild and the National Association of Science Writers (NASW). She has recently returned to the United States after living abroad for six years and has just published her first book, DIRTY MINDS: HOW OUR BRAINS INFLUENCE LOVE, SEX AND RELATIONSHIPS, an exploration of the neurobiology of love (Free Press, 2012).

When you’re pregnant, it’s not just our belly getting bigger and your butt getting bigger and your feet getting bigger, just everything getting bigger. There’s more going on. Your brain is also going through some changes.

In fact, Pelion Kim, who is a researcher, found that there is actually volume changes in the brain. Different areas of the brain, including the parietal lobes, prefrontal cortex, and other areas, actually get bigger. And it fits in pretty well with research that’s also been done in rodent models. And what they find is, forget this idea of the mommy brain that being a mom makes you stupid. It’s actually that the brain rearranges so you can be a better parent. So you’re better prepared for both the challenges and rewards of being a parent.

So, mommy rats, hands down, they are faster than non-moms at catching prey, at navigating mazes, at getting back to their babies. So there’s something going on there that really prepares them. Not only that, they don’t like cocaine anymore. So in these really interesting bar press tests, usually rats go nuts for cocaine as they would for sugar pellets. But when they can bar press for pups, they’d rather have that than the cocaine. It’s almost like the brain has changed so they prefer their babies to anything else.

I think it makes a lot of sense because having babies is a lot of commitment. You have this screaming, pooping, you know, helpless little baby that really, you’re going to be totally responsible for, for several years. Maybe even beyond 18 years these days. And if you didn’t have these brain changes to prepare you for it, you’d probably leave them on the side of the road and let them fend for themselves. So there are a lot of changes going on; we’re just beginning to understand them.

I think what’s become clear is that, like romantic love, this is something that changes the risk and the reward processing circuit of the brain. So, of course, it’s making us care for these helpless infants, it’s helping us prepare for the challenges and the rewards, and it allows us to forget what a pain in the butt it was so we actually do it again.